U.S. patent application number 16/477969 was filed with the patent office on 2020-04-23 for light-receiving device, method of manufacturing light receiving device, imaging device, and electronic apparatus.
This patent application is currently assigned to SONY SEMICONDUCTOR SOLUTIONS CORPORATION. The applicant listed for this patent is SONY SEMICONDUCTOR SOLUTIONS CORPORATION. Invention is credited to Nobutoshi FUJII, Suguru SAITO.
Application Number | 20200127039 16/477969 |
Document ID | / |
Family ID | 62979468 |
Filed Date | 2020-04-23 |
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United States Patent
Application |
20200127039 |
Kind Code |
A1 |
SAITO; Suguru ; et
al. |
April 23, 2020 |
LIGHT-RECEIVING DEVICE, METHOD OF MANUFACTURING LIGHT RECEIVING
DEVICE, IMAGING DEVICE, AND ELECTRONIC APPARATUS
Abstract
There is provided a light-receiving device including: a
plurality of photoelectric conversion layers including a first
photoelectric conversion layer and a second photoelectric
conversion layer disposed in respective regions that are different
in a planar view; an insulating film that separates the plurality
of photoelectric conversion layers from one another; a first
inorganic semiconductor material included in the first
photoelectric conversion layer; and a second inorganic
semiconductor material included in the second photoelectric
conversion layer, and different from the first inorganic
semiconductor material.
Inventors: |
SAITO; Suguru; (Kanagawa,
JP) ; FUJII; Nobutoshi; (Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SONY SEMICONDUCTOR SOLUTIONS CORPORATION |
Kanagawa |
|
JP |
|
|
Assignee: |
SONY SEMICONDUCTOR SOLUTIONS
CORPORATION
Kanagawa
JP
|
Family ID: |
62979468 |
Appl. No.: |
16/477969 |
Filed: |
December 19, 2017 |
PCT Filed: |
December 19, 2017 |
PCT NO: |
PCT/JP2017/045422 |
371 Date: |
July 15, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 27/146 20130101;
H01L 27/14669 20130101; H01L 27/14609 20130101; H04N 5/33 20130101;
H01L 31/02 20130101; H01L 27/14625 20130101; H01L 27/14683
20130101; H01L 27/144 20130101; H04N 5/369 20130101 |
International
Class: |
H01L 27/146 20060101
H01L027/146; H04N 5/33 20060101 H04N005/33 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 24, 2017 |
JP |
2017-010187 |
Claims
1. A light-receiving device comprising: a plurality of
photoelectric conversion layers including a first photoelectric
conversion layer and a second photoelectric conversion layer
disposed in respective regions that are different in a planar view;
an insulating film that separates the plurality of photoelectric
conversion layers from one another; a first inorganic semiconductor
material included in the first photoelectric conversion layer; and
a second inorganic semiconductor material included in the second
photoelectric conversion layer, and different from the first
inorganic semiconductor material.
2. The light-receiving device according to claim 1, wherein a
thickness of the first photoelectric conversion layer is different
from a thickness of the second photoelectric conversion layer.
3. The light-receiving device according to claim 1, further
comprising a third photoelectric conversion layer provided in a
thickness direction of the first photoelectric conversion layer,
and overlapping a portion of the first photoelectric conversion
layer in a planar view, wherein the third photoelectric conversion
layer includes a third inorganic semiconductor material different
from the first inorganic semiconductor material.
4. The light-receiving device according to claim 1, wherein the
first photoelectric conversion layer or the second photoelectric
conversion layer or both are configured to generate electric
charges through absorbing light of a wavelength in an infrared
region.
5. The light-receiving device according to claim 1, wherein the
first photoelectric conversion layer or the second photoelectric
conversion layer or both are configured to generate electric
charges through absorbing light of a wavelength in a visible
region.
6. The light-receiving device according to claim 1, wherein the
first inorganic semiconductor material or the second inorganic
semiconductor material or both include one of Ge, InGaAs,
Ex.InGaAs, InAsSb, InAs, InSb, and HgCdTe.
7. The light-receiving device according to claim 1, further
comprising: a first electrode electrically coupled to each of the
first photoelectric conversion layer and the second photoelectric
conversion layer; and a ROIC (readout integrated circuit) substrate
electrically coupled to each of the first electrodes.
8. The light-receiving device according to claim 7, further
comprising a first contact layer provided between the first
electrode and each of the first photoelectric conversion layer and
the second photoelectric conversion layer.
9. The light-receiving device according to claim 8, wherein
surfaces in contact with the first electrodes of a plurality of the
first contact layers are flush with one another.
10. The light-receiving device according to claim 7, further
comprising a second electrode opposed to the first electrode with
each of the first photoelectric conversion layer and the second
photoelectric conversion layer interposed therebetween.
11. The light-receiving device according to claim 10, further
comprising a second contact layer provided between the second
electrode and each of the first photoelectric conversion layer and
the second photoelectric conversion layer.
12. The light-receiving device according to claim 11, wherein
surfaces in contact with the second electrode of a plurality of the
second contact layers are flush with one another.
13. The light-receiving device according to claim 10, wherein the
second electrode is provided common to the first photoelectric
conversion layer and the second photoelectric conversion layer.
14. The light-receiving device according to claim 1, wherein a size
of the first photoelectric conversion layer is different from a
size of the second photoelectric conversion layer in a planar
view.
15. A method of manufacturing a light-receiving device, the method
comprising: of a plurality of photoelectric conversion layers
disposed in respective regions that are different in a planar view,
and separated from one another by an insulating film, forming a
first photoelectric conversion layer including a first inorganic
semiconductor material; and forming a second photoelectric
conversion layer including a second inorganic semiconductor
material different from the first inorganic semiconductor
material.
16. The method of manufacturing the light-receiving device
according to claim 15, wherein the first photoelectric conversion
layer and the second photoelectric conversion layer are formed
through forming the insulating film having a first opening and a
second opening on a substrate, and epitaxially growing the first
inorganic semiconductor material in the first opening, and the
second inorganic semiconductor material in the second opening.
17. The method of manufacturing the light-receiving device
according to claim 16, wherein a hard mask is used to cover each of
the second opening in epitaxially growing the first inorganic
semiconductor material in the first opening, and the first opening
in epitaxially growing the second inorganic semiconductor material
in the second opening.
18. An imaging device comprising: a plurality of photoelectric
conversion layers including a first photoelectric conversion layer
and a second photoelectric conversion layer disposed in respective
regions that are different in a planar view; an insulating film
that separates the plurality of photoelectric conversion layers
from one another; a first inorganic semiconductor material included
in the first photoelectric conversion layer; and a second inorganic
semiconductor material included in the second photoelectric
conversion layer, and different from the first inorganic
semiconductor material.
19. An electronic apparatus provided with an imaging device, the
imaging device comprising: a plurality of photoelectric conversion
layers including a first photoelectric conversion layer and a
second photoelectric conversion layer disposed in respective
regions that are different in a planar view; an insulating film
that separates the plurality of photoelectric conversion layers
from one another; a first inorganic semiconductor material included
in the first photoelectric conversion layer; and a second inorganic
semiconductor material included in the second photoelectric
conversion layer, and different from the first inorganic
semiconductor material.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a light-receiving device
to be used, for example, for an infrared sensor, etc. and a method
of manufacturing the same, and to an imaging device and an
electronic apparatus.
BACKGROUND ART
[0002] In recent years, an image sensor (an infrared sensor) having
sensitivity in an infrared region has been commercialized. For
example, as described in PTL 1, in a light-receiving device used
for this infrared sensor, a photoelectric conversion layer
including, for example, a Group III-V semiconductor such as InGaAs
(indium gallium arsenide) is used, and in this photoelectric
conversion layer, electric charges are generated (photoelectric
conversion is performed) by absorption of an infrared ray.
CITATION LIST
Patent Literature
[0003] PTL 1: Japanese Unexamined Patent Application Publication
No. 2014-127499
SUMMARY OF THE INVENTION
[0004] As for a device structure of such a light-receiving device
or an imaging device, various proposals have been made, but it is
expected to further widen a photoelectrically convertible
wavelength band.
[0005] It is therefore desirable to provide a light-receiving
device, a method of manufacturing the light-receiving device, an
imaging device, and an electronic apparatus that make it possible
to perform photoelectric conversion in a wide wavelength hand.
[0006] A light-receiving device according to an embodiment of the
present disclosure includes: a plurality of photoelectric
conversion layers including a first photoelectric conversion layer
and a second photoelectric conversion layer disposed in respective
regions that are different in a planar view; an insulating film
that separates the plurality of photoelectric conversion layers
from one another; a first inorganic semiconductor material included
in the first photoelectric conversion layer; and a second inorganic
semiconductor material included in the second photoelectric
conversion layer, and different from the first inorganic
semiconductor material.
[0007] A method of manufacturing a light-receiving device according
to an embodiment of the present disclosure includes: of a plurality
of photoelectric conversion layers disposed in respective regions
that are different in a planar view, and separated from one another
by an insulating film, forming a first photoelectric conversion
layer including a first inorganic semiconductor material; and
forming a second photoelectric conversion layer including a second
inorganic semiconductor material different from the first inorganic
semiconductor material.
[0008] According to the light-receiving device and the method of
manufacturing the light-receiving device of the respective
embodiments, the first photoelectric conversion layer and the
second photoelectric conversion layer include the inorganic
semiconductor materials different from each other (the first
inorganic semiconductor material and the second inorganic
semiconductor material); therefore, photoelectrically convertible
wavelength is set in each of the first photoelectric conversion
layer and the second photoelectric conversion layer.
[0009] An imaging device according to an embodiment of the present
disclosure includes the above-described light-receiving device
according to the embodiment of the present disclosure.
[0010] An electronic apparatus according to an embodiment of the
present disclosure includes the above-described imaging device
according to the embodiment of the present disclosure.
[0011] According to the light-receiving device, the method of
manufacturing the light-receiving device, the imaging device, and
the electronic apparatus of the respective embodiments of the
present disclosure, the first photoelectric conversion layer and
the second photoelectric conversion layer include the inorganic
semiconductor materials different from each other, which makes it
possible to shift photoelectrically convertible wavelengths of the
first photoelectric conversion layer and the second photoelectric
conversion layer. This makes it possible to perform photoelectric
conversion in a wide wavelength band.
[0012] It is to be noted that contents described above are
illustrative. Effects to be achieved by the present disclosure are
not limited to effects described above, and may be effects other
than those described above, or may further include other effects in
addition to those described above.
BRIEF DESCRIPTION OF DRAWINGS
[0013] FIG. 1 is a cross-sectional view of a configuration of a
light-receiving device according to an embodiment of the present
disclosure.
[0014] FIG. 2A is a cross-sectional view for description of one
process of a method of manufacturing the light-receiving device
illustrated in FIG. 1.
[0015] FIG. 2B is a cross-sectional view of a process following
FIG. 2A.
[0016] FIG. 2C is a cross-sectional view of a process following
FIG. 2B.
[0017] FIG. 2D is a cross-sectional view of a process following
FIG. 2C.
[0018] FIG. 2E is a cross-sectional view of a process following
FIG. 2D.
[0019] FIG. 3A is a cross-sectional view of a process following
FIG. 2E.
[0020] FIG. 3B is a cross-sectional view of a process following
FIG. 3A.
[0021] FIG. 3C is a cross-sectional view of a process following
FIG. 3B.
[0022] FIG. 4 is a cross-sectional view of a configuration of a
light-receiving device according to a comparative example.
[0023] FIG. 5A is a cross-sectional view for description of one
process of a method of manufacturing the light-receiving device
illustrated in FIG. 4.
[0024] FIG. 5B is a cross-sectional view of a. process following
FIG. 5A.
[0025] FIG. 5C is a cross-sectional view of a process following
FIG. 5B.
[0026] FIG. 6 is a cross-sectional view of a configuration of a
light-receiving device according to a modification example 1.
[0027] FIG. 7 is a cross-sectional view of a configuration of a
light-receiving device according to a modification example 2.
[0028] FIG. 8 is a cross-sectional view of another example of the
light-receiving device illustrated in FIG. 7.
[0029] FIG. 9A is a cross-sectional view for description of one
process of a method of manufacturing the light-receiving device
illustrated in FIG. 7.
[0030] FIG. 9B is a cross-sectional view of a process following
FIG. 9A.
[0031] FIG. 9C is a cross-sectional view of a process following
FIG. 9B.
[0032] FIG. 10A is a cross-sectional view of a process following
FIG. 9C
[0033] FIG. 10B is a cross-sectional view of a process following
FIG. 10A.
[0034] FIG. 10C is a cross-sectional view of a process following
FIG. 10B.
[0035] FIG. 11 is a cross-sectional view of a configuration of a
light-receiving device according to a modification example 3.
[0036] FIG. 12 is a cross-sectional view for description of one
process of a method of manufacturing the light-receiving device
illustrated in FIG. 11.
[0037] FIG. 13 is a cross-sectional view for description of an
operation of the light-receiving device illustrated in FIG. 11.
[0038] FIG. 14 is a block diagram illustrating a configuration of
an imaging device.
[0039] FIG. 15 is a schematic diagram illustrating a configuration
example of an imaging device of a stacked type.
[0040] FIG. 16 is a functional block diagram illustrating an
example of an electronic apparatus (a camera)using the imaging
device illustrated in FIG. 14.
[0041] FIG. 17 is a view depicting an example of a schematic
configuration of an endoscopic surgery system.
[0042] FIG. 18 is a block diagram depicting an example of a
functional configuration of a camera head and a camera control unit
(CCU).
[0043] FIG. 19 is a block diagram depicting an example of schematic
configuration of a vehicle control system,
[0044] FIG. 20 is a diagram of assistance in explaining an example
of installation positions of an outside-vehicle information
detecting section and an imaging section.
MODES FOR CARRYING OUT THE INVENTION
[0045] Some embodiments of the present disclosure are described
below in detail with reference to the drawings. It is to be noted
that the description is given in the following order. [0046] 1.
Embodiment (An example of a light-receiving device including a
photoelectric conversion layer that includes inorganic
semiconductor materials different from each other) [0047] 2.
Modification Example 1 (An example including photoelectric
conversion layers different in size from each other in a planar
view) [0048] 3. Modification Example 2 (An example in which a light
incident surface is flat) [0049] 4. Modification Example 3 (An
example of light dispersion in a longitudinal direction) [0050] 5.
Application Example 1 (An example of an imaging device) [0051] 6.
Application Example 2 (An example of an electronic apparatus)
[0052] 7. Further Application Example 1 (A further application
example to an endoscopic surgery system) [0053] 8. Further
Application Example 2 (A further application example to a mobile
body)
EMBODIMENT
[Configuration]
[0054] FIG. 1 illustrates a cross-sectional configuration of a
light-receiving device (a light-receiving device 1) of an
embodiment of the present disclosure. The light-receiving device 1
is applied, for example, to an infrared sensor, etc. using an
inorganic semiconductor material such as a Group III-V
semiconductor, and includes a plurality of light-receiving unit
regions P (pixels P1, P2, P3, P4, P5, . . . Pn) two-dimensionally
arranged, for example. It is to be noted that FIG. 1 illustrates a
cross-sectional configuration of a portion corresponding to five
pixels P (the pixels P1 to P5).
[0055] The light-receiving device 1 includes a ROTC (readout
integrated circuit) substrate 11. In the light-receiving device 1,
a first electrode 21, a first contact layer 22, a photoelectric
conversion layer 23, a second contact layer 24, and a second
electrode 25 are provided in this order on this ROIC substrate 11.
The first electrode 21, the first contact layer 22, the
photoelectric conversion layer 23, and the second contact layer 24
are provided separately for each of the pixels P, and the second
electrode 25 is provided common to the plurality of pixels P. In
the light-receiving device 1, light (e.g., light of wavelengths in
a visible region and an infrared region) incident on the
photoelectric conversion layer 23 from side of the second electrode
25. For example, light of a wavelength in the visible region is
photoelectrically converted in each of the pixels P1 to P3, and
light of a wavelength in the infrared region is photoelectrically
converted in each of the pixels P4 and PS.
[0056] The light-receiving device 1 includes a protective film 12
between the first electrode 21 and the ROTC substrate 11, and the
protective film 12 is provided with a through electrode 12E coupled
to the first electrode 21. The light-receiving device 1 includes an
insulating film 13 between adjacent ones of the pixels P. The
light-receiving device 1 includes a passivation film 14 and a color
filter layer 15 in this order on the second electrode 25, and in
the light-receiving device 1, light having passed through the color
filter layer 15 and the passivation film 14 is incident on the
photoelectric conversion layer 23. A configuration of each portion
is described below. It is to be noted that the pixels P1 to P5 have
similar configurations except for the photoelectric conversion
layer 23, and the description of each portion except for the
photoelectric conversion layer 23 is thus common to the respective
pixels P.
[0057] The ROIC substrate 11 includes, for example, a silicon (Si)
substrate and a multilayered wiring layer disposed. on the silicon
substrate, and this multilayered wiring layer is provided with an
ROIC. In the multilayered wiring layer, at a position close to the
protective film 12, an electrode including, for example, copper
(Cu) is provided for each of the pixels P, and this electrode is in
contact with the through electrode 12E.
[0058] The first electrode 21 serves as an electrode (anode) that
is supplied with a voltage for readout of signal charges (holes or
electrons; hereinafter described as holes for convenience)
generated in the photoelectric conversion layer 23, and is provided
for each of the pixels P. The first electrode 21 is smaller than
the first contact layer 22 in a planar view, and is in contact with
a substantially central portion of the first contact layer 22. One
first electrode 21 is disposed for a corresponding one of the
pixels P. and the first electrodes 21 in adjacent ones of the
pixels P are electrically separated from each other by the
protective film 12.
[0059] The first electrode 21 includes, for example, a simple
substance of any of titanium (Ti), tungsten (W), titanium nitride
(TiN), platinum (Pt), gold (Au), germanium (Ge), palladium (Pd),
zinc (Zn), nickel (Ni), and aluminum (Al), or an alloy including at
least one of these materials. The first electrode 21 may include a
single layer film of any of the above-described constituent
materials, or may include a stacked film including a combination of
two or more of the above-described constituent materials.
[0060] The first contact layer 22 is provided between the first
electrode 21 and the photoelectric conversion layer 23, and is in
contact with the first electrode 21 and the photoelectric
conversion layer 23. One first contact layer 22 is disposed for a
corresponding one of the pixels P, and the first contact layers 22
in adjacent ones of the pixels P are electrically separated from
each other by the insulating film 13. The first contact layer 22
serve as a region where the signal charges generated in the
photoelectric conversion layer 23 move, and includes, for example,
an inorganic semiconductor material including a p-type impurity.
For example, it possible to use InP (indium phosphide) including a
p-type impurity such as Zn (zinc), for the first contact layer 22.
For example, the first contact layers 22 each have a surface in
contact with the first electrode 21, and the surfaces of the first
contact layers 22 in the pixels P are flush with one another. In
other words, of the plurality of first contact layers 22, the
surfaces in contact with the first electrodes 21 are flush with one
another.
[0061] The photoelectric conversion layer 23 between the first
electrode 21 and the second electrode 25 absorbs light of a
predetermined wavelength to generate signal charges, and includes
an inorganic semiconductor material such as a Group III-V
semiconductor. Examples of the inorganic semiconductor material
included in the photoelectric conversion layer 23 include Ge
(germanium), InGaAs (indium gallium arsenide), Ex.InGaAs, InAsSb
(indium arsenide antimonide), InAs (indium arsenide), InSb (indium
antimonide), and HgCdTe (mercury cadmium tellurium). One
photoelectric conversion layer 23 is disposed for a corresponding
one of the pixels P, and the photoelectric conversion layers 23 in
adjacent ones of the pixels P are electrically separated from each
other by the insulating film 13. Specifically, the pixel P1 is
provided with a photoelectric conversion layer 23A, the pixel P2 is
provided with a photoelectric conversion layer 23B, the pixel P3 is
provided with a photoelectric conversion layer 23C, the pixel P4 is
provided with a photoelectric conversion layer 23D, and the pixel
P5 is provided with a photoelectric conversion layer 23E. In other
words, the photoelectric conversion layers 23A to 23E are disposed
at respective positions that are different in a planar view. In the
present embodiment, the inorganic semiconductor material included
in the photoelectric conversion layer 23A (or the photoelectric
conversion layers 23B to 23D) is different from the inorganic
semiconductor material included in the photoelectric conversion
layer 23E. This makes it possible to perform photoelectric
conversion in a wide wavelength band, as described in detail later.
Here, the photoelectric conversion layer 23E corresponds to a
specific example of a first photoelectric conversion layer of the
present technology, and the photoelectric conversion layer 23A (or
the photoelectric conversion layers 239 to 23D) corresponds to a
specific example of a second photoelectric conversion layer of the
present technology.
[0062] The photoelectric conversion layers 23A, 23B, and 23C mainly
perform photoelectric conversion of light of wavelengths in the
visible region. Light in a blue wavelength region (e.g., a
wavelength in a range of 500 nm or less) is absorbed in the
photoelectric conversion layer 23A, light in a green wavelength
region (e.g., a wavelength in a range of 500 nm to 600 nm) is
absorbed in the photoelectric conversion layer 239, and light in a
red wavelength region (e.g., a wavelength in a range of 600 nm to
800 nm) is absorbed in the photoelectric conversion layer 23C, and
signal charges are thereby generated. These photoelectric
conversion layers 23A to 23C include, for example, a Group III-V
semiconductor of an i-type. Examples of the Group III-V
semiconductor used for the photoelectric conversion layers 23A to
23C include InGaAs (indium gallium arsenide). For example, the
photoelectric conversion layers 23A, 23B, and 23C have respective
thicknesses different from one another. For example, the thickness
of the photoelectric conversion layer 23A is the smallest, and the
thicknesses of the photoelectric conversion layer 23B and the
photoelectric conversion layer 23C are larger in this order. For
example, the thickness of the photoelectric conversion layer 23A is
500 nm or less, the thickness of the photoelectric conversion layer
23B is 700 nm or less, and the thickness of the photoelectric
conversion layer 23C is 800 nm or less.
[0063] The photoelectric conversion layer 23D mainly performs
photoelectric conversion of light of a wavelength in a short
infrared region (e.g., a wavelength in a range of 1 .mu.m to 10
.mu.m). This photoelectric conversion layer 23D includes, for
example, a Group III-V semiconductor of the i-type, and includes,
for example, InGaAs (indium gallium arsenide). The photoelectric
conversion layer 23D is, for example, thicker than the
photoelectric conversion layers 23A to 23C, and the photoelectric
conversion layer 23D has a thickness of, for example, 1 .mu.m to 10
.mu.m.
[0064] The photoelectric conversion layer 23E mainly performs
photoelectric conversion of light of a wavelength in an
intermediate infrared region (e.g., a wavelength in a range of 3
.mu.m to 10 .mu.m). This photoelectric conversion layer 23E
includes, a Group III-V semiconductor of the i-type that is
different from those of the photoelectric conversion layers 23A to
23D. Specifically, it is possible to use InAsSb (indium arsenide
antimonide), InSb (indium antimonide), or the like for the
photoelectric conversion layer 23E. In this way, in the pixel P
(the pixel P5), the inorganic semiconductor material different from
those of the photoelectric conversion layers 23 in the other pixels
P is used, which makes it possible to photoelectrically convert
light in a longer wavelength region. It is therefore possible to
achieve high photoelectric conversion efficiency in a wide
wavelength band. For example, the thickness of the photoelectric
conversion layer 23E is different from the thicknesses of the
photoelectric conversion layers 23A to 23C, and is, for example, 3
.mu.m to 10 .mu.m.
[0065] The second contact layer 24 is provided between the
photoelectric conversion layer 23 and the second electrode 25, and
is in contact with the photoelectric conversion layer 23 and the
second electrode 25. One second contact layer 24 is disposed for a
corresponding one of the pixels P, and the second contact layers 24
in adjacent ones of the pixels P are electrically separated from
each other by the insulating film 13. The second contact layer 24
serves as a region where electric charges discharged from the
second electrode 25 move, and includes, for example, a compound
semiconductor including an n-type impurity. For example, it
possible to use InP (indium phosphide) including an n-type impurity
such as Si (silicon), for the second contact layer 24.
[0066] The second electrode 25 is provided as, for example, an
electrode that is common to the respective pixels P on the second
contact layer 24 (light incident side) to be in contact with the
second contact layer 24. The second electrode 25 discharges
electric charges that are not used as signal charges of the
electric charges generated in the photoelectric conversion layer 23
(cathode). For example, in a case where holes are read from the
first electrode 21 as signal charges, it is possible to discharge,
for example, electrons through this second electrode 25. The second
electrode 25 includes, for example, a conductive film that allows
incident light such as an infrared ray to pass therethrough. It is
possible to use, for example, ITO (Indium Tin Oxide), ITiO
(In.sub.2O.sub.3--TiO.sub.2), or the like for the second electrode
25.
[0067] The protective film 12 is provided to cover one surface (a
surface on the light incident side) of the ROIC substrate 11. The
protective film 12 includes, for example, an inorganic insulating
material. Examples of this inorganic insulating material include
silicon nitride (SiN), aluminum oxide (Al.sub.2O.sub.3), silicon
oxide (SiO.sub.2), hafnium oxide (HfO.sub.2), etc, The protective
film 12 may have a stacked structure including a plurality of
films. The through electrode 12E provided in the protective film 12
couples a wiring line of the ROIC substrate 11 to the first
electrode 21, and is provided for each of the pixels P. The through
electrode 12E includes, for example, copper,
[0068] For example, the insulating film 13 covers a side surface of
the first contact layer 22, a side surface of the photoelectric
conversion layer 23, and a side surface of the second contact layer
24, in each of the pixels P. This insulating film 13 separates the
photoelectric conversion layers 23 adjacent to each other for each
of the pixels P, and a region between the photoelectric conversion
layers 23 adjacent to each other is filled with the insulating film
13. The insulating film 13 includes, for example, an oxide such as
silicon oxide (SiO.sub.x) or aluminum oxide Al.sub.2O.sub.3), The
insulating film 13 may include a stacked structure including a
plurality of films. The insulating film 13 may include, for
example, a silicon (Si)-based insulating material such as silicon
oxynitride (SiON), carbon-containing silicon oxide (SiOC), silicon
nitride (SiN), and silicon carbide (SiC).
[0069] The passivation film 14 covers the second electrode 25, and
is provided between the second electrode 25 and the color filter
layer 15. This passivation film 14 may have an antireflection
function. It possible to use, for example, silicon nitride (SiN),
aluminum oxide (Al.sub.2O.sub.3), silicon oxide (SiO.sub.2).
tantalum oxide (Ta.sub.2O.sub.3), etc., for the passivation film
14.
[0070] The color filter layer 15 is provided on the passivation
film 14 (on light incident surface side of the passivation film
14). The color filter layer 15 includes, for example, a blue filter
in the pixel P1, a green filter in the pixel P2, and a red filter
in the pixel P3. For example, light of wavelengths in the infrared
region is photoelectrically converted in the pixels P4 and P5 and
thus, the color filter layer 15 may include a visible-light cut
filter in the pixels P4 and P5.
[0071] The light-receiving device 1 may include, on the color
filter layer 15, an on-chip lens (for example, an on-chip lens 17
in FIG. 8 described later) to condense incident light toward the
photoelectric conversion layer 23.
[Method of Manufacturing Light Receiving Device 1]
[0072] It is possible to manufacture the light-receiving device 1
as follows, for example. FIGS. 2A to 3C illustrate manufacturing
processes of the light-receiving device 1 in process order. FIGS.
2A to 3C each depict a region corresponding to the pixels P3 to
P5.
[0073] First, a substrate 31 including, for example, silicon (Si)
is prepared, and the insulating film 13 including, for example,
silicon oxide (SiO.sub.2,) or silicon nitride (SiN) is formed on
this substrate 31.
[0074] Next, as illustrated in FIG. 2A, an opening (openings 13C to
13E corresponding to the pixels P3 to P5) is formed in a region
corresponding to each of the pixels P of the formed insulating film
13, and the second contact layer 24 is formed in this opening.
Specifically, the following is performed. First, the insulating
film 13 is patterned through using, for example, photolithography
and dry etching to form the openings 13C to 13E. The openings 13C
to 13E are formed for the respective pixels P, and each include
portions a1 and a2 having respective open widths different from
each other. The portion a2 is an opening portion where the
photoelectric conversion layer 23 is formed in a later process, and
has a depth adjusted for each of the pixels P in accordance with
the thickness of the formed photoelectric conversion layer 23. The
thickness of the photoelectric conversion layer 23 is thus adjusted
by the depth of the portion a2, which makes it possible to
manufacture the light-receiving device 1 easily. The portion a1 has
a higher aspect ratio than the portion a2, and is formed as a
trench or an aperture within the portion a2. The aspect ratio of
the portion a1 is, for example, 1.5 or more. The portion a1
penetrates the insulating film 13 from the portion a2, and is also
provided in a portion (a portion on side of the insulating film 13)
of the substrate 31.
[0075] Of the portion a1, an exposed surface of a substrate 51 is
subjected to, for example, alkali anisotropic etching. In this
etching, for example, crystal plane orientation dependence of the
silicon substrate (the substrate 31) is strong, and an etching rate
in a (111) plane direction is extremely low. For this reason, as
for an etching processing surface, etching stops at a (111) plane,
and a plurality of (111) planes is formed.
[0076] After the etching process is performed, a buffer layer 32
including InP is formed from the plurality of (111) planes of the
substrate 31 to the portion a1 of the insulating film 13 with use
of a MOCVD (Metal Organic Chemical Vapor Deposition) method or a
MBE (Molecular Beam Epitaxy) method. Inr this way, the buffer layer
32 is epitaxially grown from the plurality of (111) planes inclined
with respect to the surface of the substrate 31, which makes it
possible to reduce defect density of the buffer layer 32. One
reason for this is that growth of stacking fault starts from an
interface between the inclined (111) plane and the buffer layer 32
in a film formation direction, but at this moment, this stacking
fault hits a wall of the insulating film 13 and thereby the growth
stops. After the buffer layer 32 is formed in the portion a1, for
example, InP is epitaxially grown in the portion a2 to form the
second contact layer 24 (FIG. 2A),
[0077] Subsequently, the photoelectric conversion layer 23 is
formed in each of the openings (the openings 13C to 13E) (FIGS. 2B
and 2C). The photoelectric conversion layer 23 is formed with use
of, for example, a hard mask 33. Specifically, the photoelectric
conversion layers 23C to 23E are formed in the openings 13C to 13E
as follows. First, in a state where the opening 13E is covered with
the hard mask 33, the photoelectric conversion layers 23C and 23D
including, for example, InGaAs (indium gallium arsenide) are formed
in the openings 13C and 13D by epitaxial growth. Thereafter, in a
state where the openings 13C and 13D are covered with the hard mask
33, the photoelectric conversion layer 23E including, for example,
InAsSb (indium arsenide antimonide) or InSb (indium antimonide) is
formed in the opening 13E by epitaxial growth.
[0078] After the photoelectric conversion layer 23 is formed, for
example, InP is epitaxially grown on the photoelectric conversion
layer 23 to form the first contact layer 22, as illustrated in FIG:
2D. Subsequently, a surface of the first contact layer 22 is
flattened by, for example, CMP (Chemical Mechanical Polishing).
[0079] Next, on the flattened surface of the first contact layer
22, a film including the constituent material of the first
electrode 21 is formed, and this film is patterned with use of
photolithography and etching. The first electrode 21 is thereby
formed (FIG. 2E).
[0080] Subsequently, the protective film 12 and the through
electrode 12E are formed. Specifically, after the protective film
12 is formed on the first electrode 21 and on the insulating film
13, a through-hole is formed in a region, corresponding to a
central portion of the first electrode 21, of this protective film
12 with use of, for example, photolithography and dry etching.
Thereafter, the through electrode 12E including, for example,
copper is formed in this through-hole.
[0081] Next, as illustrated in FIG. 3A, this through electrode 12E
is bonded to an electrode of the ROIC substrate 11. For example,
such bonding is performed by Cu--Cu bonding. Subsequently, the
substrate 31 is thinned by, for example, a grinder, and the thinned
substrate 31 and the buffer layer 32 are removed by, for example,
etching to expose a surface of the second contact layer 24 (FIG.
3B).
[0082] Finally, as illustrated in FIG. 3C, the second electrode 25,
the passivation film 14, and the color filter layer 15 are formed
in this order, thereby completing the light-receiving device 1
illustrated in FIG 1.
[Operation of Light Receiving Device 1]
[0083] In the light-receiving device 1, in a case where light
(e.g., light of wavelengths in the visible region and the infrared
region) is incident on the photoelectric conversion layer 23
through the color filter layer 15, the passivation film 14, the
second electrode 25, and the second contact layer 24, this light is
absorbed in the photoelectric conversion layer 23. A pair of a hole
(a positive hole) and an electron is thereby generated in the
photoelectric conversion layer 23 (photoelectric conversion is
performed). At this moment, in a case where, for example, a
predetermined voltage is applied to the first electrode 21, a
potential gradient occurs in the photoelectric conversion layer 23,
and one (e.g., the hole) of the generated electric charges moves to
the first contact layer 22 as a signal charge, and is collected
from the first contact layer 22 to the first electrode 21. This
signal charge is read by the ROIC substrate 11.
[Workings and Effects of Light Receiving Device 1]
[0084] In the light-receiving device 1 of the present embodiment,
the photoelectric conversion layers 23A to 23D of the pixels P1 to
P4 and the photoelectric conversion layer 23E of the pixel P5
include the inorganic semiconductor materials different from each
other. In addition, it is possible to adjust the thicknesses of the
respective photoelectric conversion layers 23A to 23D to be
different from one another. This makes it easy to set a
photoelectrically convertible wavelength band in each of the
photoelectric conversion layers 23A to 23E (the pixels P1 to P5).
For example, it is possible to provide such a configuration in
which photoelectric conversion is performed for the light in the
blue wavelength region in the photoelectric conversion layer 23A
(the pixel P1), the light in the green wavelength region in the
photoelectric conversion layer 23B (the pixel P2), the light in the
red wavelength region in the photoelectric conversion layer 23C
(the pixel P3), the light of the wavelength in the short infrared
region in the photoelectric conversion layer 23D (the pixel P4),
and the light of the wavelength in the intermediate infrared region
in the photoelectric conversion layer 23E (the pixel P5). This is
described below.
[0085] FIG. 4 illustrates a cross-sectional configuration of a
light-receiving device (a light-receiving device 100) according to
a comparative example. In this light-receiving device 100, adjacent
ones of the pixels P are not separated from each other by an
insulating film. and a first contact layer 122, a photoelectric
conversion layer 123, a second contact layer 124, and a second
electrode 125 are provided common to all the pixels P. A first
electrode 121 is separated for each of the pixels P.
[0086] FIGS. 5A to 5C illustrate manufacturing processes of this
light-receiving device 100. For the light-receiving device 100,
first, the photoelectric conversion layer 123 and the first contact
layer 122 are formed on a substrate 124A by, for example, epitaxial
growth (FIG. 5A) and then, the protective film 12 and a through
electrode (not illustrated) are formed. Next, this through
electrode and the electrode of the ROIC substrate 11 are bonded to
each other by, for example, Cu--Cu bonding (FIG. 5B), Thereafter,
for example, the substrate 124A is thinned to form the second
contact laser 124 (FIG. 5C). Finally, for example, the second
electrode 125, a passivation film, and a color filter layer are
formed, thereby forming the light-receiving device 100.
[0087] In the light-receiving device 100 thus formed, it is
difficult to vary a constituent material of the photoelectric
conversion layer 123, or to vary a thickness of the photoelectric
conversion layer 123, from one pixel P to another. For this reason,
in the light-receiving device 100, light in the same wavelength
region is photoelectrically converted in all the pixels P, and it
is not possible to perform photoelectric conversion selectively on
light in a wavelength region different for each of the pixels
P.
[0088] In contrast, in the light-receiving device 1, the
photoelectric conversion layers 23A to 23E of the constituent
materials different from one another, or of the different
thicknesses, are provided and it is thus possible to perform
photoelectric conversion selectively on light in a wavelength
region different for each of the pixels P. For example,
photoelectric conversion is performed selectively on the light of
the wavelength in the visible region in each of the pixels P1 to
P3, the light of the wavelength in the short infrared region in the
pixel P4, and the light of the wavelength in the intermediate
infrared region in the pixel P5. It is possible to form such a
light-receiving device 1 easily, through forming the photoelectric
conversion layer 23 in the opening (e.g., the openings 13C to 13E
in FIG. 24) provided in the insulating film 13 for each of the
pixels P.
[0089] As described above, in the light-receiving device 1 of the
present embodiment, the photoelectric conversion layers 23A to 23D
and the photoelectric conversion layer 23E include the inorganic
semiconductor materials different from each other, which makes it
possible to shift the photoelectrically convertible wavelengths of
the photoelectric conversion layers 23A to 23D and the
photoelectric conversion layer 23E. In addition, the thicknesses
are different among the photoelectric conversion layers 23A to 23D,
and it is thus possible to shift the photoelectrically convertible
wavelengths. It is therefore possible to perform photoelectric
conversion in a wide wavelength band.
[0090] Modification examples and application examples of the
foregoing embodiment are described below, and the same components
as those of the foregoing embodiment are denoted by the same
reference numerals, and the descriptions thereof are omitted where
appropriate.
MODIFICATION EXAMPLE 1
[0091] FIG. 6 illustrates a cross-sectional configuration of a
light-receiving device (a light-receiving device 1A) according to a
modification example 1 of the foregoing embodiment. As in the
light-receiving device 1A, the photoelectric conversion layers 23
having different widths (widths W3 and W4) may be provided. Except
for this point, the light-receiving device 14 has a configuration
and effects similar to those of the light-receiving device 1.
[0092] For example, in the light-receiving deuce 1A, the width W4
of the photoelectric conversion layer 23D is larger than the width
W3 of the photoelectric conversion layer 23C. For example, the
width of each of the photoelectric conversion layers 23A and 23B is
substantially the same as the width W3, and the width of the
photoelectric conversion layer 23E is larger than the width W4. For
example, the photoelectric conversion layer 23C and the
photoelectric conversion layer 23D have different sizes in a planar
view, and also have different lengths (sizes in a direction
orthogonal to the widths W3 and W4). Only either the widths W3 and
W4 or the lengths may be different between the photoelectric
conversion layer 23C and the photoelectric conversion layer
23D.
MODIFICATION EXAMPLE 2
[0093] FIG. 7 illustrates a cross-sectional configuration of a
light-receiving device (a light-receiving device 1B) according to a
modification example 2. In the foregoing embodiment, the case where
the surface on side of the ROIC substrate 11 (specifically, the
surface, in contact with the first electrode 21, of the first
contact layer 22) is flat is described as an example, but the
surface on the light incident side may be flat. Specifically, as in
the light-receiving device 1B, the second contact layers 24 may
each have a surface in contact with the second electrode 25 and the
surfaces of the second contact layers 24 in the pixels P may be
flush with one another. In other words, in the light-receiving
device 1B, of the plurality of second contact layers 24, the
surfaces in contact with the second electrode 25 are flush with one
another. Except for this point, the light-receiving device 13 has a
configuration and effects similar to those of the light-receiving
device 1.
[0094] As illustrated in FIG. 8, the light-receiving device 1B may
include an on-chip lens (the on-chip lens 17). The on-chip lens 17
is provided, for example, on the color filter layer 15, with a
passivation film 16 interposed therebetween. In this way, in the
light-receiving device 1B in which the light incident surface is
flat, a focus design of the on-chip lens 17 is easy, and it is
possible to form the on-chip lens 17 easily.
[0095] It is possible to manufacture the light-receiving device 1B
as follows, for example. FIGS. 9A to IOC illustrate manufacturing
processes of the light-receiving device 1B in process order. FIGS.
9A to 10C each depict a region corresponding to the pixels P1 to
P3.
[0096] First, in a manner similar to the manner described in the
foregoing embodiment, an opening (openings 134 to 13C corresponding
to the pixels P1 to P3) is formed in the region, corresponding to
each of the pixels P, of the insulating film 13, and the second
contact layer 24 is formed in this opening (FIG. 9A). At this
moment, the depth of the portion a2 are the same in the pixels P,
and thereby, of the second contact layers 24, the surfaces in
contact with the second electrode 25 in the pixels P are flush with
one another.
[0097] Next, the photoelectric conversion layer 23 is formed in
each of the openings (the openings 13A to 13C) (FIG: 9B). For
example, the photoelectric conversion layers 234 to 23C are formed
through epitaxially growing InGaAs (indium gallium arsenide) and
thereafter adjusting thicknesses of InGaAs for the respective
pixels P by etching.
[0098] After the photoelectric conversion layer 23 is formed, the
first contact layer 22 and the first electrode 21 are formed in
this order on the photoelectric conversion layer 23, as illustrated
in FIG. 9C. Subsequently, the protective film 12 and the through
electrode 12E are formed and then, this through electrode 12E is
bonded to the electrode of the ROIC substrate 11, as illustrated in
FIG. 104.
[0099] Thereafter, the substrate 31 is thinned, and the substrate
31 and the buffer layer 32 are removed by, for example, etching to
expose the surface of the second contact layer 24 (FIG. 10B).
[0100] Finally, as illustrated in FIG. 10C, the second electrode
25, the passivation film 14, and the color filter layer 15 are
formed in this order, thereby completing the light-receiving device
1B illustrated in FIG. 7.
[0101] As in the present modification example, the surface on the
light incident surface side may be flat among the pixels P, and
even in this case, it is possible to obtain effects similar to the
effects of the foregoing embodiment. In addition, the focus design
of the on-chip lens 17 is easy.
MODIFICATION EXAMPLE 3
[0102] FIG. 11 illustrates a cross-sectional configuration of the
pixel PS in a light-receiving device (a light-receiving device 1C)
according to a modification example 3. As in the present
modification example, another photoelectric conversion layer (a
photoelectric conversion layer 23EA) may be stacked in a thickness
direction of the photoelectric conversion layer 23E. In such a
light-receiving device 1C, light dispersion in a longitudinal
direction is possible. Except for this point, the light-receiving
device 1C has a configuration and effects similar to those of the
light-receiving device 1.
[0103] The photoelectric conversion layer 23E4 (a third
photoelectric conversion layer) is stacked in the thickness
direction of the photoelectric conversion layer 23E, and is
provided at a position where a portion of the photoelectric
conversion layer 23EA overlaps the photoelectric conversion layer
23E in a planar view. The photoelectric conversion layer 23EA
includes an inorganic semiconductor material different from the
material of the photoelectric conversion layer 23E. For example,
the photoelectric conversion layer 23EA mainly performs
photoelectric conversion of light of a wavelength in the short
infrared region, and includes InGaAs (indium gallium arsenide). The
pixel P5 is provided, for example, with two photoelectric
conversion layers 23EA, and these photoelectric conversion layers
23E4 are disposed at the same position in the thickness direction.
The pixel P5 may be provided with one photoelectric conversion
layer 23EA, or may be provided with three or more photoelectric
conversion lavers 23EA.
[0104] A surface, opposed to the ROIC substrate 11, of the
photoelectric conversion layer 23EA is provided with a first
electrode 21A, and the first electrode 21A is coupled to the ROIC
substrate 11 through a through electrode 12EA in the insulating
film 13. A first contact layer 22A is provided between the
photoelectric conversion layer 23E4 and the first electrode 21A. A
second contact layer 24A and the second electrode 25 are stacked in
this order on a light incident surface of the photoelectric
conversion layer 23EA.
[0105] FIG. 12 illustrates one process in manufacturing the
light-receiving device 1C. It is possible to form the
light-receiving device 1C in a manner similar to the manner
described in the foregoing embodiment.
[0106] In the light-receiving device 1C, as illustrated in FIG. 13,
for example, in the one pixel P5, light L1 of a wavelength in the
intermediate infrared region is photoelectrically converted by the
photoelectric conversion layer 23E, and, for example, light L2 of a
wavelength in the short infrared region is photoelectrically
converted by the photoelectric conversion layer 23EA.
[0107] As in the present modification example, a plurality of
photoelectric conversion layers (e.g., the photoelectric conversion
layer 23E and the photoelectric conversion layer 23EA) may be
provided in a stacking direction in one pixel P. Even in this case,
it is possible to obtain effects similar to those of the
above-described first embodiment. In addition, because light
dispersion in the longitudinal direction is possible within the one
pixel P, which makes it easy to make the pixel P finer
[0108] FIG. 11 illustrates the case where the photoelectric
conversion layer 23EA is provided in the pixel P5, but the
photoelectric conversion layer 23EA may be provided in the pixel P5
as well as any other pixel P (e.g., the pixels P1 to P4).
Alternatively, the photoelectric conversion layer 23EA may be
provided in another pixels P without being provided in the pixel
P5.
APPLICATION EXAMPLE 1
[0109] FIG. 14 illustrates a functional configuration of an imaging
device 2 using an device structure of the light-receiving device 1
(or the light-receiving devices 1A to 1C, hereinafter collectively
referred to as the light-receiving device 1) described in the
foregoing embodiment, etc. Examples of the imaging device 2 include
an infrared image sensor, and the imaging device 2 includes, for
example, a pixel section 131 including the light-receiving device
1, and a circuit section 20 that drives this pixel section 10P. The
circuit section 20 includes, for example, a row scanner 131, a
horizontal selector 133, a column scanner 134, and a system
controller 132.
[0110] The pixel section 10P includes, for example, the plurality
of pixels P (the light-receiving devices 1) arranged
two-dimensionally in a matrix. For example, the pixels P are wired
with pixel drive lines Lread (specifically, row selection lines and
reset control lines) for respective pixel rows, and wired with
vertical signal lines Lsig for respective pixel columns. The pixel
drive lines Lread transmit drive signals for signal reading from
the pixels P. The pixel drive lines each have one end coupled to a
corresponding one of output terminals, corresponding to the
respective rows, of the row scanner 131.
[0111] The row scanner 131 serves as a pixel driver that includes a
shift register, an address decoder, etc., and drives each of the
pixels P of the pixel section 10 on a row-by-row basis, for
example. A signal outputted from each of the pixels P of a pixel
row selected and scanned by the row scanner 131 is supplied to the
horizontal selector 133 through each of the vertical signal lines
Lsig. The horizontal selector 133 includes an amplifier, a
horizontal selection switch, etc. provided for each of the vertical
signal lines Lsig.
[0112] The column scanner 134 includes a shift register, an address
decoder, etc., and sequentially drives respective horizontal
selection switches of the horizontal selector 133 while scanning
the horizontal selection switches. Such selective scanning by the
column scanner 134 causes signals of the respective pixels
transmitted through the respective vertical signal lines Lsig to be
outputted in sequence to a horizontal signal line 135 and
thereafter inputted to an unillustrated signal processor, etc.
through the horizontal signal line 135.
[0113] In this imaging device 2, as illustrated in FIG. 15, for
example, a substrate 2A including the pixel section 10P and a
substrate 2B (e.g., the ROIC substrate 11 in FIG. 1) including the
circuit section 20 are stacked. However, such a configuration is
not limitative, and the circuit section 20 may be formed on the
same substrate as the substrate of the pixel section 10P, or may be
disposed in an external control IC. Further, the circuit section 20
may be formed in another substrate coupled by a cable, etc.
[0114] The system controller 132 receives a clock provided from
outside, data to command an operation mode, etc., and also outputs
data such as internal information of the imaging device 2. The
system controller 132 further includes a timing generator that
generates various timing signals, and performs driving control of
the row scanner 131, the horizontal selector 133, the column
scanner 134, etc., on the basis of the various timing signals
generated by this timing generator,
APPLICATION EXAMPLE 2
[0115] The above-described imaging device 2 is applicable to
various types of electronic apparatuses such as a camera that
enables imaging of, for example, an infrared region. FIG. 16
illustrates a schematic configuration of an electronic apparatus 3
(a camera), as an example. Examples of the electronic apparatus 3
include a camera that enables of shooting of a still image or a
moving image, and the electronic apparatus 3 includes the imaging
device 2, an optical system (an optical lens) 310, a shutter
apparatus 311, a driver 313 that drives the imaging device 2 and
the shutter apparatus 311, and a signal processor 312.
[0116] The optical system 310 guides image light (incident light)
from a subject to the imaging device 2. This optical system 310 may
include a plurality of optical lenses. The shutter apparatus 311
controls a period in which the imaging device 2 is irradiated with
the light and a period in which the light is blocked. The driver
313 controls a transfer operation of the imaging device 2 and a
shutter operation of the shutter apparatus 311, The signal
processor 312 performs various kinds of signal processing on a
signal outputted from the imaging device 2. An image signal Dout
having been subjected to the signal processing is stored in a
storage medium such as a memory or outputted to a monitor, etc.
[0117] Further, the light-receiving device 1 described in the
present embodiment, etc. is also applicable to the following
electronic apparatuses (a capsule endoscope and a mobile body such
as a vehicle).
FURTHER APPLICATION EXAMPLE 1 (ENDOSCOPIC SURGERY SYSTEM)
[0118] The technology according to the present disclosure (the
present technology) is applicable to various products. For example,
the technology according to the present disclosure may be applied
to an endoscopic surgery system.
[0119] FIG. 17 is a view depicting an example of a schematic
configuration of an endoscopic surgery system to which the
technology according to an embodiment of the present disclosure
(present technology) can be applied.
[0120] In FIG. 17, a state is illustrated in which a surgeon
(medical doctor) 11131 is using an endoscopic surgery system 11000
to perform surgery for a patient 11132 on a patient bed 11133. As
depicted, the endoscopic surgery system 11000 includes an endoscope
11100, other surgical tools 11110 such as a pneumoperitoneum tube
11111 and an energy device 11112, a supporting arm apparatus 11120
which supports the endoscope 11100 thereon, and a cart 11200 on
which various apparatus for endoscopic surgery are mounted.
[0121] The endoscope 11100 includes a lens barrel 11101 having a
region of a predetermined length from a distal end thereof to be
inserted into a body cavity of the patient 11132, and a camera head
11102 connected to a proximal end of the lens barrel 11101. In the
example depicted, the endoscope 11100 is depicted which includes as
a rigid endoscope having the lens barrel 11101 of the hard type.
However, the endoscope 11100 may otherwise be included as a
flexible endoscope having the lens barrel 11101 of the flexible
type.
[0122] The lens barrel 11101 has, at a distal end thereof, an
opening in which an objective lens is fitted. A light source
apparatus 11203 is connected to the endoscope 11100 such that light
generated by the light source apparatus 11203 is introduced to a
distal end of the lens barrel 11101 by a light guide extending in
the inside of the lens barrel 11101 and is irradiated toward an
observation target in a body cavity of the patient 11132 through
the objective lens. it is to be noted that the endoscope 11100 may
be a forward-viewing endoscope or may be an oblique-viewing
endoscope or a side-viewing endoscope.
[0123] An optical system and an image pickup element are provided
in the inside of the camera head 11102 such that reflected light
(observation light) from the observation target is condensed on the
image pickup element by the optical system. The observation light
is photo-electrically converted by the image pickup element to
generate an electric signal corresponding to the observation light,
namely, an image signal corresponding to an observation image. The
image signal is transmitted as RAW data to a CCU 11201.
[0124] The CCU 11201 includes a central processing unit (CPU), a
graphics processing unit (GPU) or the like and integrally controls
operation of the endoscope 11100 and a display apparatus 11202.
Further, the CCU 11201 receives an image signal from the camera
head 11102 and performs, for the image signal, various image
processes for displaying an image based on the image signal such
as, for example, a development process (demosaic process).
[0125] The display apparatus 11202 displays thereon an image based
on an image signal, for which the image processes have been
performed by the CCU 11201, under the control of the CCU 11201.
[0126] The light source apparatus 11203 includes a light source
such as, for example, a light emitting diode (LED) and supplies
irradiation light upon imaging of a surgical region to the
endoscope 11100.
[0127] An inputting apparatus 11204 is an input interface for the
endoscopic surgery system 11000. A user can perform inputting of
various kinds of information or instruction inputting to the
endoscopic surgery system 11000 through the inputting apparatus
11204. For example, the user would input an instruction or a like
to change an image pickup condition (type of irradiation light,
magnification, focal distance or the like) by the endoscope
11100.
[0128] A treatment tool controlling apparatus 11205 controls
driving of the energy device 11112 for cautery or incision of a
tissue, sealing of a blood vessel or the like. A pneumoperitoneum
apparatus 11206 feeds gas into a body cavity of the patient 11132
through the pneumoperitoneum tube 11111 to inflate the body cavity
in order to secure the field of view of the endoscope 11100 and
secure the working space for the surgeon. A recorder 11207 is an
apparatus capable of recording various kinds of information
relating to surgery. A printer 11208 is an apparatus capable of
printing various kinds of information relating to surgery in
various forms such as a text, an image or a graph.
[0129] It is to be noted that the light source apparatus 11203
which supplies irradiation light when a surgical region is to be
imaged to the endoscope 11100 may include a white light source
which includes, for example. an LED, a laser light source or a
combination of them. Where a white light source includes a
combination of red, green, and blue (RGB) laser light sources,
since the output intensity and the output timing can be controlled
with a high degree of accuracy for each color (each wavelength),
adjustment of the white balance of a picked up image can be
performed by the light source apparatus 11203. Further, in this
case, if laser beams from the respective RGB laser light sources
are irradiated time-divisionally on an observation target and
driving of the image pickup elements of the camera head 11102 are
controlled in synchronism with the irradiation timings. Then images
individually corresponding to the R, G and B colors can be also
picked up time-divisionally. According to this method, a color
image can be obtained even if color filters are not provided for
the image pickup element.
[0130] Further, the light source apparatus 11203 may be controlled
such that the intensity of light to be outputted is changed for
each predetermined time. By controlling driving of the image pickup
element of the camera head 11102 in synchronism with the timing of
the change of the intensity of light to acquire images
time-divisionally and synthesizing the images, an image of a high
dynamic range free from underexposed blocked up shadows and
overexposed highlights can be created.
[0131] Further, the light source apparatus 11203 may be configured
to supply light of a predetermined wavelength band ready for
special light observation. In special light observation, for
example, by utilizing the wavelength dependency of absorption of
light in a body tissue to irradiate light of a narrow band in
comparison with irradiation light upon ordinary observation
(namely, white light), narrow band observation (narrow band
imaging) of imaging a predetermined tissue such as a blood vessel
of a superficial portion of the mucous membrane or the like in a
high contrast is performed. Alternatively, in special light
observation, fluorescent observation for obtaining an image from
fluorescent light generated by irradiation of excitation light may
be performed. In fluorescent observation, it is possible to perform
observation of fluorescent light from a body tissue by irradiating
excitation light on the body tissue (autofluorescence observation)
or to obtain a fluorescent light image by locally injecting a
reagent such as indocyanine green (ICG) into a body tissue and
irradiating excitation light corresponding to a fluorescent light
wavelength of the reagent upon the body tissue. The light source
apparatus 11203 can be configured to supply such narrow-band light
and/or excitation light suitable for special light observation as
described above.
[0132] FIG. 18 is a block diagram depicting an example of a
functional configuration of the camera head 11102 and the CCU 11201
depicted in FIG. 17.
[0133] The camera head 11102 includes a lens unit 11401, an image
pickup unit 11402, a driving unit 11403, a communication unit 11404
and a camera head controlling unit 11405. The CCU 11201 includes a
communication unit 11411, an image processing unit 11412 and a
control unit 11413. The camera head 11102 and the CCU 11201 are
connected for communication to each other by a transmission cable
11400.
[0134] The lens unit 11401 is an optical system, provided at a
connecting location to the lens barrel 11101. Observation light
taken in from a distal end of the lens barrel 11101 is guided to
the camera head 11102 and introduced into the lens unit 11401. The
lens unit 11401 includes a combination of a plurality of lenses
including a zoom lens and a focusing lens.
[0135] The number of image pickup elements which is included by the
image pickup unit 11402 may be one (single-plate type) or a plural
number (multi-plate type). Where the image pickup unit 11402 is
configured as that of the multi-plate type, for example, image
signals corresponding to respective R, G and B are generated by the
image pickup elements, and the image signals may be synthesized to
obtain a color image, The image pickup unit 11402 may also be
configured so as to have a pair of image pickup elements for
acquiring respective image signals for the right eye and the left
eye ready for three dimensional (3D) display. If 3D display is
performed, then the depth of a living body tissue in a surgical
region can be comprehended more accurately by the surgeon 11131. It
is to be noted that, where the image pickup unit 11402 is
configured as that of stereoscopic type, a plurality of systems of
lens units 11401 are provided corresponding to the individual image
pickup elements.
[0136] Further, the image pickup unit 11402 may not necessarily be
provided on the camera head 11102. For example, the image pickup
unit 11402 may be provided immediately behind the objective lens in
the inside of the lens barrel 11101.
[0137] The driving unit 11403 includes an actuator and moves the
zoom lens and the focusing lens of the lens unit 11401 by a
predetermined distance along an optical axis under the control of
the camera head controlling unit 11405. Consequently, the
magnification and the focal point of a picked up image by the image
pickup unit 11402 can be adjusted suitably.
[0138] The communication unit 11404 includes a communication
apparatus for transmitting and receiving various kinds of
information o and from the CCU 11201. The communication unit 11404
transmits an image signal acquired from the image pickup unit 11402
as RAW data to the CCU 11201 through the transmission cable
11400.
[0139] In addition, the communication unit 11404 receives a control
signal for controlling driving of the camera head 11102 from the
CCU 11201 and supplies the control signal to the camera head
controlling unit 11405. The control signal includes information
relating to image pickup conditions such as, for example,
information that a frame rate of a picked up image is designated,
information that an exposure value upon image picking up is
designated and/or information that a magnification and a focal
point of a picked up image are designated.
[0140] It is to be noted that the image pickup conditions such as
the frame rate, exposure value, magnification or focal point may be
designated by the user or may be set automatically by the control
unit 11413 of the CCU 11201 on the basis of an acquired image
signal. In the latter case, an auto exposure (AE) function, an auto
focus (AF) function and an auto white balance (AWB) function are
incorporated in the endoscope 11100.
[0141] The camera head controlling unit 11405 controls driving of
the camera head 11102 on the basis of a control signal from the CCU
11201 received through the communication unit 11404,
[0142] The communication unit 11411 includes a communication
apparatus for transmitting and receiving various kinds of
information to and from the camera head 11102. The communication
unit 11411 receives an image signal transmitted thereto from the
camera head 11102 through the transmission cable 11400.
[0143] Further, the communication unit 11411 transmits a control
signal for controlling driving of the camera head 11102 to the
camera head 11102. The image signal and the control signal can be
transmitted by electrical communication, optical communication or
the like.
[0144] The image processing unit 11412 performs various image
processes for an image signal in the form of RAW data transmitted
thereto from the camera head 11102.
[0145] The control unit 11413 performs various kinds of control
relating to image picking up of a surgical region or the like by
the endoscope 11100 and display of a picked up image obtained by
image picking up of the surgical region or the like. For example,
the control unit 11413 creates a control signal for controlling
driving of the camera head 11102.
[0146] Further, the control unit 11413 controls, on the basis of an
Image signal for which image processes have been performed by the
image processing unit 11412, the display apparatus 11202 to display
a picked up image in which the surgical region or the like is
imaged. Thereupon, the control unit 11413 may recognize various
objects in the picked up image using various image recognition
technologies. For example, the control unit 11413 can recognize a
surgical tool such as forceps, a particular living body region,
bleeding, mist when the energy device 11112 is used and so forth by
detecting the shape, color and so forth of edges of objects
included in a picked up image. The control unit 11413 may cause,
when it controls the display apparatus 11202 to display a picked up
image, various kinds of surgery supporting information to be
displayed in an overlapping manner with an image of the surgical
region using a result of the recognition. Where surgery supporting
information is displayed in an overlapping manner and presented to
the surgeon 11131, the burden on the surgeon 11131 can be reduced
and the surgeon 11131 can proceed with the surgery with
certainty.
[0147] The transmission cable 11400 which connects the camera head
11102 and the CCU 11201 to each other is an electric signal cable
ready for communication of an electric signal, an optical fiber
ready for optical communication or a composite cable ready for both
of electrical and optical communications.
[0148] Here, while, in the example depicted, communication is
performed by wired communication using the transmission cable
11400, the communication between the camera head 11102 and the CCU
11201 may be performed by wireless communication.
[0149] In the foregoing, the description has been given of one
example of the endoscopic surgery system to which the technology
according to the present disclosure is applicable. The technology
according to the present disclosure may be applied to the image
pickup unit 11402 among the components of the configuration
described above. Applying the technology according to the present
disclosure to the image pickup unit 11402 makes it possible to
obtain a clearer image of the surgical region. Hence, it is
possible for the surgeon to confirm the surgical region with
certainty.
[0150] Note that the description has been given above of the
endoscopic surgery system as one example. The technology according
to the present disclosure may be applied to any medical system
besides the endoscopic surgery system, such as a micrographic
surgery system.
FURTHER APPLICATION EXAMPLE 2 (MOBILE BODY)
[0151] The technology according to the present disclosure is
applicable to various products, For example, the technology
according to the present disclosure may be achieved in the form of
an apparatus to be mounted to a mobile body of any kind such as an
automobile, an electric vehicle, a hybrid electric vehicle, a
motorcycle, a bicycle, a personal mobility, an airplane, a drone, a
vessel, and a robot.
[0152] FIG. 19 is a block diagram depicting an example of schematic
configuration of a vehicle control system as an example of a mobile
body control system to which the technology according to an
embodiment of the present disclosure can be applied.
[0153] The vehicle control system 12000 includes a plurality of
electronic control units connected to each other via a
communication network 12001. In the example depicted in FIG. 19,
the vehicle control system 12000 includes a driving system control
unit 12010, a body system control unit 12020, an outside-vehicle
information detecting unit 12030, an in-vehicle information
detecting unit 12040, and an integrated control unit 12050. in
addition, a microcomputer 12051, a sound/image output section
12052, and a vehicle-mounted network interface (I/F) 12053 are
illustrated as a functional configuration of the integrated control
unit 12050.
[0154] The driving system control unit 12010 controls the operation
of devices related to the driving system of the vehicle in
accordance with various kinds of programs. For example, the driving
system control unit 12010 functions as a control device for a
driving force generating device for generating the driving force of
the vehicle, such as an internal combustion engine, a driving
motor, or the like, a driving force transmitting mechanism for
transmitting the driving force to wheels, a steering mechanism for
adjusting the steering angle of the vehicle, a braking device for
generating the braking force of the vehicle, and the like.
[0155] The body system control unit 12020 controls the operation of
various kinds of devices provided to a vehicle body in accordance
with various kinds of programs. For example, the body system
control unit 12020 functions as a control device for a keyless
entry system, a smart key system, a power window device, or various
kinds of lamps such as a headlamp, a backup lamp, a brake lamp, a
turn signal, a fog lamp, or the like. In this case, radio waves
transmitted from a mobile device as an alternative to a key or
signals of various kinds of switches can be input to the body
system control unit 12020. The body system control unit 12020
receives these input radio waves or signals, and controls a door
lock device, the power window device, the lamps, or the like of the
vehicle.
[0156] The outside-vehicle information detecting unit 12030 detects
information about the outside of the vehicle including the vehicle
control system 000. For example, the outside-vehicle information
detecting unit 12030 is connected with an imaging section 12031.
The outside-vehicle information detecting unit 12030 makes the
imaging section 12031 image an image of the outside of the vehicle,
and receives the imaged image. On the basis of the received image,
the outside-vehicle information detecting unit 12030 may perform
processing of detecting an object such as a human, a vehicle, an
obstacle, a sign, a character on a road surface, or the like, or
processing of detecting a distance thereto.
[0157] The imaging section 12031 is an optical sensor that receives
light, and which outputs an electric signal corresponding to a
received light amount of the light. The imaging section 12031 can
output the electric signal as an image, or can output the electric
signal as information about a measured distance. In addition, the
light received by the imaging section 12031 may be visible light,
or may be invisible light such as infrared rays or the like.
[0158] The in-vehicle information detecting unit 12040 detects
information about the inside of the vehicle. The in-vehicle
information detecting unit 12040 is, for example, connected with a
driver state detecting section 12041 that detects the state of a
driver. The driver state detecting section 12041, for example,
includes a camera that images the driver. On the basis of detection
information input from the driver state detecting section 12041,
the in-vehicle information detecting unit 12040 may calculate a
degree of fatigue of the driver or a degree of concentration of the
driver, or may determine whether the driver is dozing.
[0159] The microcomputer 12051 can calculate a control target value
for the driving force generating device, the steering mechanism, or
the braking device on the basis of the information about the inside
or outside of the vehicle which information is obtained by the
outside-vehicle information detecting unit 12030 or the in-vehicle
information detecting unit 12040, and output a control command to
the driving system control unit 12010. For example, the
microcomputer 12051 can perform cooperative control intended to
implement functions of an advanced driver assistance system (ADAS)
which functions include collision avoidance or shock mitigation for
the vehicle, following driving based on a following distance,
vehicle speed maintaining driving, a warning of collision of the
vehicle, a warning of deviation of the vehicle from a lane, or the
like.
[0160] In addition, the microcomputer 12051 can perform cooperative
control intended for automatic driving, which makes the vehicle to
travel autonomously without depending on the operation of the
driver, or the like, by controlling the driving force generating
device, the steering mechanism, the braking device, or the like on
the basis of the information about the outside or inside of the
vehicle which information is obtained by the outside-vehicle
information detecting unit 12030 or the in-vehicle information
detecting unit 12040.
[0161] In addition, the microcomputer 12051 can output a control
command to the body system control unit 12020 on the basis of the
information about the outside of the vehicle which information is
obtained by the outside-vehicle information detecting unit 12030.
For example, the microcomputer 12051 can perform cooperative
control intended to prevent a glare by controlling the headlamp so
as to change from a high beam to a low beam, for example, in
accordance with the position of a preceding vehicle or an oncoming
vehicle detected by the outside-vehicle information detecting unit
12030.
[0162] The sound/image output section 12052 transmits an output
signal of at least one of a sound and an image to an output device
capable of visually or auditorily notifying information to an
occupant of the vehicle or the outside of the vehicle. In the
example of FIG. 19, an audio speaker 12061, a display section
12062, and an instrument panel 12063 are illustrated as the output
device. The display section 12062 may, for example, include at
least one of an on-board display and a head-up display.
[0163] FIG. 20 is a diagram depicting an example of the
installation position of the imaging section 12031.
[0164] In FIG. 20, the imaging section 12031 includes imaging
sections 12101, 12102, 12103, 12104, and 12105.
[0165] The imaging sections 12101, 12102, 12103, 12104, and 12105
are, for example, disposed at positions on a front nose, sideview
mirrors, a rear bumper, and a back door of the vehicle 12100 as
well as a position on an upper portion of a windshield within the
interior of the vehicle. The imaging section 12101 provided to the
front nose and the imaging section 12105 provided to the upper
portion of the windshield within the interior of the vehicle obtain
mainly an image of the front of the vehicle 12100. The imaging
sections 12102 and 12103 provided to the sideview mirrors obtain
mainly an image of the sides of the vehicle 12100. The imaging
section 12104 provided to the rear bumper or the back door obtains
mainly an image of the rear of the vehicle 12100. The imaging
section 12105 provided to the upper portion of the windshield
within the interior of the vehicle is used mainly to detect a
preceding vehicle, a pedestrian, an obstacle, a signal, a traffic
sign, a lane, or the like,
[0166] Incidentally, FIG. 20 depicts an example of photographing
ranges of the imaging sections 12101 to 12104. An imaging range
12111 represents the imaging range of the imaging section 12101
provided to the front nose. Imaging ranges 12112 and 12113
respectively represent the imaging ranges of the imaging sections
12102 and 12103 provided to the sideview mirrors. An imaging range
12114 represents the imaging range of the imaging section 12104
provided to the rear bumper or the back door. A bird's-eye image of
the vehicle 12100 as viewed from above is obtained by superimposing
image data imaged by the imaging sections 12101 to 12104, for
example.
[0167] At least one of the imaging sections 12101 to 12104 may have
a function of obtaining distance information. For example, at least
one of the imaging sections 12101 to 12104 may be a stereo camera
constituted of a plurality of imaging elements, or may be an
imaging element having pixels for phase difference detection.
[0168] For example, the microcomputer 12051 can determine a
distance to each three-dimensional object within the imaging ranges
12111 to 12114 and a temporal change in the distance (relative
speed with respect to the vehicle 12100) on the basis of the
distance information obtained from the imaging sections 12101 to
12104, and thereby extract, as a preceding vehicle, a nearest
three-dimensional object in particular that is present on a
traveling path of the vehicle 12100 and which travels in
substantially the same direction as the vehicle 12100 at a
predetermined speed (for example, equal to or more than 0 km/hour).
Further, the microcomputer 12051 can set a following distance to be
maintained in front of a preceding vehicle in advance, and perform
automatic brake control (including following stop control),
automatic acceleration control (including following start control),
or the like. It is thus possible to perform cooperative control
intended for automatic driving that makes the vehicle travel
autonomously without depending on the operation of the driver or
the like.
[0169] For example, the microcomputer 12051 can classify
three-dimensional object data on three-dimensional objects into
three-dimensional object data of a two-wheeled vehicle, a
standard-sized vehicle, a large-sized vehicle, a pedestrian, a
utility pole, and other three-dimensional objects on the basis of
the distance information obtained from the imaging sections 12101
to 12104, extract he classified three-dimensional object data, and
use the extracted three-dimensional object data for automatic
avoidance of an obstacle. For example, the microcomputer 12051
identifies obstacles around the vehicle 12100 as obstacles that the
driver of the vehicle 12100 can recognize visually and obstacles
that are difficult for the driver of the vehicle 12100 to recognize
visually. Then, the microcomputer 12051 determines a collision risk
indicating a risk of collision with each obstacle. In a situation
in which the collision risk is equal to or higher than a set value
and there is thus a possibility of collision, the microcomputer
12051 outputs a warning to the driver via the audio speaker 12061
or the display section 12062, and performs forced deceleration or
avoidance steering via the driving system control unit 12010. The
microcomputer 12051 can thereby assist in driving to avoid
collision.
[0170] At least one of the imaging sections 12101 to 12104 may be
an infrared camera that detects infrared rays. The microcomputer
12051 can, for example, recognize a pedestrian by determining
whether or not there is a pedestrian in imaged images of the
imaging sections 12101 to 12104. Such recognition of a pedestrian
is, for example, performed by a procedure of extracting
characteristic points in the imaged images of the imaging sections
12101 to 12104 as infrared cameras and a. procedure of determining
whether or not it is the pedestrian by performing pattern matching
processing on a series of characteristic points representing the
contour of the object. When the microcomputer 12051 determines that
there is a pedestrian in the imaged images of the imaging sections
12101 to 12104, and thus recognizes the pedestrian, the sound/image
output section 12052 controls the display section 12062 so that a
square contour line for emphasis is displayed so as to be
superimposed on the recognized pedestrian. The sound/image output
section 12052 may also control the display section 12062 so that an
icon or the like representing the pedestrian is displayed at a
desired position.
[0171] In the foregoing, the description has been given of one
example of the vehicle control system, to which the technology
according to the present disclosure is applicable. The technology
according to the present disclosure may be applied to, for example,
the imaging section 12031 among components of the configuration
described above. Applying the technology according to the present
disclosure to the imaging section 12031 makes it possible to obtain
a captured image that is easier to see. Hence, it is possible to
reduce fatigue of the driver
[0172] Furthermore, the light-receiving device 1 described in the
present embodiment, etc is applicable to electronic apparatuses
such as a surveillance camera, a biometric authentication system,
and a thermograph. Examples of the surveillance camera include a
camera of a night vision system (night vision). Applying the
light-receiving device 1 to the surveillance camera makes it
possible to recognize a pedestrian and an animal at night from a
distance. Further, influences of a headlight and weather are
reduced by application of the light-receiving device 1 to a
vehicle-mounted camera. For example, it is possible to capture an
image by shooting without influences of smoke, fog, etc.
Furthermore, it is also possible to recognize shape of an object.
Moreover, in the thermography, it is possible to perform
non-contact temperature measurement. The thermograph allows for
detection of a temperature distribution and heat generation, In
addition, the light-receiving device 1 is also applicable to
electronic apparatuses that detect fire, water, gas, etc.
[0173] The embodiment and the application examples are described
above, but the present disclosure contents are not limited to the
foregoing embodiment, etc., and may be modified in a variety of
ways. For example, the layer configuration of the light-receiving
device described in the foregoing embodiment is merely exemplified,
and any other layer may be further provided. In addition, the
material and the thickness of each layer are also merely
exemplified, and are not limited to the foregoing.
[0174] For example, in the foregoing embodiment, etc., description
has been give of the case where the first electrode 21 and the
first contact layer 22 are in contact with. each other and the
second contact layer 24 and the second electrode 25 are in contact
with each other, but any other layer may be provided between the
first electrode 21 and the first contact layer 22 or between the
second contact layer 24 and the second electrode 25.
[0175] Further, in the foregoing. embodiment, etc., the case where
the signal charges are holes is described for convenience, but the
signal charges may be electrons. The first contact layer 22 may
include an n-type impurity, and the second contact layer 24 may
include a p-type impurity.
[0176] Moreover, the effects described in the foregoing embodiment,
etc. are merely exemplified, and may be any other effects or may
further include any other effects.
[0177] It is to be noted that the present disclosure may have the
following configurations.
[0178] (1) A light-receiving device including: [0179] a plurality
of photoelectric conversion layers including a first photoelectric
conversion layer and a second photoelectric conversion layer
disposed in respective regions that are different in a planar view;
[0180] an insulating film that separates the plurality of
photoelectric conversion layers from one another; [0181] a first
inorganic semiconductor material included in the first
photoelectric conversion layer; and [0182] a second inorganic
semiconductor material included in the second photoelectric
conversion layer, and different from the first inorganic
semiconductor material.
[0183] (2) The light-receiving device according to (1), in which a
thickness of the first photoelectric conversion layer is different
from a thickness of the second photoelectric conversion layer.
[0184] (3) The light-receiving device according to (1) or (2),
further including a third photoelectric conversion layer provided
in a thickness direction of the first photoelectric conversion
layer, and overlapping a portion of the first photoelectric
conversion layer in a planar view, in which [0185] the third
photoelectric conversion layer includes a third inorganic
semiconductor material different from the first inorganic
semiconductor material.
[0186] (4) The light-receiving device according to any one of (1)
to (3), in which the first photoelectric conversion layer or the
second photoelectric conversion layer or both are configured to
generate electric charges through absorbing light of a wavelength
in an infrared region.
[0187] (5) The light-receiving device according to any one of (1)
to (4), in which the first photoelectric conversion layer or the
second photoelectric conversion layer or both are configured to
generate electric charges through absorbing light of a wavelength
in a visible region.
[0188] (6) The light-receiving device according to any one of (1)
to (5), in which the first inorganic semiconductor material or the
second inorganic semiconductor material or both include one of Ge,
InGaAs, ExInGaAs, InAsSb, InAs, InSb, and HgCdTe.
[0189] (7) The light-receiving device according to any one of (1)
to (6), further including: [0190] a first electrode electrically
coupled to each of the first photoelectric conversion layer and the
second photoelectric conversion layer; and [0191] a ROIC (readout
integrated circuit) substrate electrically coupled to each of the
first electrodes.
[0192] (8) The light-receiving device according to (7), further
including a first contact layer provided between the first
electrode and each of the first photoelectric conversion layer and
the second photoelectric conversion layer.
[0193] (9) The light-receiving device according to (8), in which
surfaces in contact with the first electrodes of a plurality of the
first contact layers are flush with one another.
[0194] (10) The light-receiving device according to any one of (7)
to (9), further including a second electrode opposed to the first
electrode with ach of the first photoelectric conversion layer and
the second photoelectric conversion layer interposed
therebetween.
[0195] (11) The light-receiving device according to (10), further
including a second contact layer provided between the second
electrode and each of the first photoelectric conversion layer and
the second photoelectric conversion layer.
[0196] (12) The light-receiving device according to (11), in which
surfaces in contact with the second electrode of a plurality of the
second contact layers are flush with one another.
[0197] (13) The light-receiving device according to any one of (10)
to (12), in which the second electrode is provided common to the
first photoelectric conversion layer and the second photoelectric
conversion layer.
[0198] (14) The light-receiving device according to any one of (1)
to (13), in which a size of the first photoelectric conversion
layer is different from a size of the second photoelectric
conversion layer in a planar view.
[0199] (15) A method of manufacturing a light-receiving device, the
method including: [0200] of a plurality of photoelectric conversion
layers disposed in respective regions that are different in a
planar view, and separated from one another by an insulating film,
[0201] forming a first photoelectric conversion layer including a
first inorganic semiconductor material; and [0202] forming a second
photoelectric conversion layer including a second inorganic
semiconductor material different from the first inorganic
semiconductor material.
[0203] (16) The method of manufacturing the light-receiving device
according to (15), in which the first photoelectric conversion
layer and the second photoelectric conversion layer are formed
through [0204] forming the insulating film having a first opening
and a second opening on a substrate, and [0205] epitaxially growing
the first inorganic semiconductor material in the first opening,
and the second inorganic semiconductor material in the second
opening.
[0206] (17) The method of manufacturing the light-receiving device
according to (16), in which a hard mask is used to cover each of
the second opening in epitaxially growing the first inorganic
semiconductor material in the first opening, and the first opening
in epitaxially growing the second inorganic semiconductor material
in the second opening.
[0207] (18) An imaging device including: [0208] a plurality of
photoelectric conversion layers including a first photoelectric
conversion layer and a second photoelectric conversion layer
disposed in respective regions that are different in a planar view;
[0209] an insulating film that separates the plurality of
photoelectric conversion layers from one another; [0210] a first
inorganic semiconductor material included in the first
photoelectric conversion layer; and [0211] a second inorganic
semiconductor material included in the second photoelectric
conversion layer, and different from the first inorganic
semiconductor material.
[0212] (19) An electronic apparatus provided with an imaging
device, the imaging device including: [0213] a plurality of
photoelectric conversion layers including a first photoelectric
conversion layer and a second photoelectric conversion layer
disposed in respective regions that are different in a planar view;
[0214] an insulating film that separates the plurality of
photoelectric conversion layers from one another; [0215] a first
inorganic semiconductor material included in the first
photoelectric conversion layer; and [0216] a second inorganic
semiconductor material included in the second photoelectric
conversion layer, and different from the first inorganic
semiconductor material.
[0217] This application claims the benefit of Japanese Priority
Patent Application JP2017-I0187 filed with the Japan Patent Office
on Jan. 24, 2017, the entire contents of which are incorporated
herein by reference.
[0218] It should be understood by those skilled in the art that
various modifications, combinations, sub-combinations, and
alterations may occur depending on design requirements and other
factors insofar as they are within the scope of the appended claims
or the equivalents thereof
* * * * *